In each of the last twoyears, I’ve presented the AV-adjusted age of each roster in the NFL. Measuring team age in the NFL is tricky. You don’t want to calculate the average age of a 53-man roster and call that the “team age” because the age of a team’s starters is much more relevant than the age of a team’s reserves. The average age of a team’s starting lineup isn’t perfect, either. The age of the quarterback and key offensive and defensive players should count for more than the age of a less relevant starter. Ideally, you want to calculate a team’s average age by placing greater weight on the team’s most relevant players.

My solution has been to use the Approximate Value numbers from Pro-Football-Reference.com. The table below shows the average age of each team, along with its average AV-adjusted age of the offense and defense. Here’s how to read the Rams’ line. In 2013, St. Louis was the youngest team in the league, with an AV-adjusted team age of 25.5 years (all ages are measured as of September 1, 2013). The average AV-adjusted age of the offense was 25.9 years, giving the Rams the third youngest offense in the NFL. The average age of the defense was 25.2 years, and that was the youngest of any defense in football in 2013.

Last week, I wrote about how the 2012 Redskins were powered by a pair of rookies in Robert Griffin III and Alfred Morris. The only team whose rookies had more passing/rushing/receiving yards in NFL history was the 2012 Colts, while the only non-expansion team with a higher percentage of yards from rookies was the ’55 Colts.

In the comments, Shattenjager pointed out that the list I presented was pretty quarterback-heavy. So I thought a fun thing to do would be to use PFR’s Approximate Value (AV) system instead of yards, and re-run the numbers.

The table below shows all non-expansion teams since 1950 that had at least 25% of their AV come from rookies. For each team, I’ve listed their record and winning percentage, total team AV, their rookie AV, and the percentage compiled by rookies. Then I listed their top four rookies in terms of AV.[click to continue…]

For the most part, age is rarely discussed when talking about college quarterbacks. Outside of the Brandon Weedens and Chris Weinkes of the world, you generally don’t hear much from the draft community about the age of a prospect. But we do know that age matters, and that all other things being equal, being younger is better (or a sign that the player has a higher ceiling).

In this year’s draft, Tyler Bray is the neophyte, as he’ll be 21 years and 8 months old at the start of the season. He’s just weeks older than Matt Stafford and Josh Freeman were this time four years ago. It also means he’s 10 months younger than Geno Smith, the second youngest of the top prospects. On the other hand, Tyler Wilson will be 24 when the season starters, Landry Jones just turned 24, and Jordan “did you know Aaron is my brother” Rodgers will be 25 on August 30th. Do NFL teams generally ignore age — i.e., fail to measure younger quarterbacks against a lower bar? Or perhaps do they overemphasize age, thinking a young player has such high upside and can be taught anything that they ignore red flags? That’s what this post seeks to answer.[click to continue…]

First, I grouped together all tackles who entered the league since 1970 and recorded at least four seasons with an Approximate Value of at least 8 points (Ferguson has three seasons with an AV of 8 and two more with an AV of 9). That gave me a group of 78 tackles who were above-average players in their prime. As it turns out, they didn’t age very well as a group, and the results probably underestimate the true effects of age.

As I’ve discussed before, there are two ways to measure group production over a number of a seasons. In the graph below, the red line shows the aging patterns of top tackles when you divide their total AV accumulated by tackles at that age by 78; the blue line shows the age curves when you divide the total AV accumulated only by those tackles active in the NFL at that age.[click to continue…]

The first step in trying to measure the aging patterns of quarterbacks is to figure out a sample to analyze. I decided to look at all quarterbacks who entered the league since 1970 and have since retired. I further limited my sample to quarterbacks who had at least three seasons of above-average play based on this system. That brought us to a group of 77 quarterbacks, from quarterbacks like Jon Kitna, Jay Fiedler, and Dan Pastorini to Hall of Famers like Joe Montana, Brett Favre, and Dan Marino.

While before I graded quarterbacks based on how much value over average they provided, that baseline is too high for this type of post. Instead, I gave quarterbacks credit for their value over replacement, defined as 75% of the league average. I then calculated the best three seasons of value over replacement (VOR) for each quarterback’s career to get a sense of their peak level of play. The last step was to divided their VOR in each season of their career by their peak value. Do this for each of the 77 quarterbacks, and we can get a sense of quarterback aging patterns.

There is another thing to consider when coming up with an age curve: The intuitive way is to sum up each quarterback’s value (relative to his peak) in each season and divide that total by the number of quarterbacks active at that age. Another way is to divide that total by 77, the number of quarterbacks in the study. The former method will make really young and really old ages look closer to average than they really are, but I have decided to include both methods in the picture below. The blue line represents the average performance based on the number of quarterbacks actually playing in the NFL that season; the red line shows the aging patterns when you divide by the total number of passers in the group.[click to continue…]

Measuring team age in the N.F.L. is tricky. Calculating the average age of a 53-man roster is misleading because the age of a team’s starters is much more relevant than the age of a team’s reserves. The average age of a team’s starting lineup isn’t perfect, either. The age of the quarterback and key offensive and defensive players should count for more than the age of a less relevant starter. Ideally, you would want to calculate a team’s average age by placing greater weight on the team’s most relevant players.

That’s not easy to do for the 2012 season, but we can apply one method to last year’s rosters. Using Pro-Football-Reference’s Approximate Value system, it’s simple to calculate the weighted age of every team last season, by weighing each player’s age proportionately to his percentage of contribution (as measured by the Approximate Value system) to his team.

Let’s take a look at the (weighted) average age of each offense last season: